In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selec...In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst.This catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)configuration.Compared to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the reaction.Within the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis acids.This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene selectivity.Through this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.展开更多
Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herei...Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.展开更多
Surface Lewis acid-base sites in crystal structure may influence the physicochemical properties and the catalytic performances in nanozymes.Understanding the synergistic effect mechanism of Co_(3)O_(4)nanozymes toward...Surface Lewis acid-base sites in crystal structure may influence the physicochemical properties and the catalytic performances in nanozymes.Understanding the synergistic effect mechanism of Co_(3)O_(4)nanozymes towards substances(3,3’,5,5’-tetramethylbenzidine(TMB)and hydrogen peroxide(H2O2))induced by surface Lewis acid-base sites is important to enhance the efficiency for peroxidase-like reaction.Herein,ultrathin porous Co_(3)O_(4)nanosheets with abundant Lewis acid-base sites were prepared by sodium borohydride(NaBH4)reduction treatment,which exhibited high-efficiency peroxidase-like activity compared with original Co_(3)O_(4)nanosheets.The Lewis acid-base sites for ultrathin porous Co_(3)O_(4)nanosheets nanozyme were owing to the coordination unsaturation of Co ions and the formation of defect structure.Ultrathin porous Co_(3)O_(4)nanosheets had 18.26-fold higher catalytic efficiency(1.27×10^(-2)s^(-1)·mM^(-1))than that of original Co_(3)O_(4)(6.95×10^(-4)s^(-1)·mM^(-1))in oxidizing TMB substrate.The synergistic effect of surface acid and base sites can enhance the interfacial electron transfer process of Co_(3)O_(4)nanosheets,which can be a favor of absorption substrates and the generation of reactive intermediates such as radicals.Furthermore,the limit of detection of hydroquinol was 0.58μM for ultrathin porous Co_(3)O_(4)nanosheets,965-fold lower than original Co_(3)O_(4)(560μM).Besides,the linear range of ultrathin porous Co_(3)O_(4)nanosheets was widely with the concentration of 5.0-1,000μM.Colorimetric detection of hydroquinol by agarose-based hydrogel membrane was provided based on excellent peroxidase-like properties.This study provided insights into designing high-performance nanozymes for peroxidase-like catalysis via a strategy of solid surface acid-base sites engineering.展开更多
The systematic method for constructing Lewis representations is a method for representing chemical bonds between atoms in a molecule. It uses symbols to represent the valence electrons of the atoms involved in the bon...The systematic method for constructing Lewis representations is a method for representing chemical bonds between atoms in a molecule. It uses symbols to represent the valence electrons of the atoms involved in the bond. Using a number of rules in a defined order, it is often better suited to complicated cases than the Lewis representation of atoms. This method allows us to determine the formal charge and oxidation number of each atom in the edifice more efficiently than other methods.展开更多
目的探讨血府逐瘀胶囊联合顺铂对小鼠Lewis肺癌移植瘤血管新生及血管内皮生长因子A(VEGFA)、血管内皮细胞生长因子受体2(VEGFR2)表达的影响。方法从75只C57BL/6小鼠中随机取15只作为正常组,其余小鼠均进行Lewis肺癌荷瘤造模。将造模成功...目的探讨血府逐瘀胶囊联合顺铂对小鼠Lewis肺癌移植瘤血管新生及血管内皮生长因子A(VEGFA)、血管内皮细胞生长因子受体2(VEGFR2)表达的影响。方法从75只C57BL/6小鼠中随机取15只作为正常组,其余小鼠均进行Lewis肺癌荷瘤造模。将造模成功的60只小鼠随机分为模型组、顺铂组、血府逐瘀胶囊组、血府逐瘀胶囊联合顺铂组,每组15只。血府逐瘀胶囊组给予血府逐瘀胶囊0.36 g/kg灌胃,模型组给予生理盐水灌胃,均2次/d;顺铂组给予2 mg/kg的顺铂腹腔注射,2 d 1次;血府逐瘀胶囊联合顺铂组给予0.36 g/kg血府逐瘀胶囊灌胃(2次/d)和2 mg/kg的顺铂腹腔注射(2 d 1次);正常组不给予任何干预。各组连续干预15 d后,统计存活率,摘取瘤组织并称量瘤重,计算抑瘤率,免疫组化法检测肿瘤组织中微血管数量,ELISA法测定血浆VEGFA、碱性成纤维细胞生长因子(bFGF)水平,免疫印迹法检测肿瘤组织中VEGFA、VEGFR2蛋白表达情况。结果顺铂组和血府逐瘀胶囊联合顺铂组小鼠存活率明显高于模型组和血府逐瘀胶囊组(P均<0.05);血府逐瘀胶囊联合顺铂组瘤重明显低于其他组(P均<0.05),抑瘤率明显高于顺铂组和血府逐瘀胶囊组(P均<0.05),肿瘤组织中微血管数明显少于模型组和血府逐瘀胶囊组(P均<0.05);顺铂组瘤重明显低于模型组和血府逐瘀胶囊组(P均<0.05),抑瘤率明显高于血府逐瘀胶囊组(P<0.05),肿瘤组织中微血管数明显少于其他组(P均<0.05)。顺铂组血浆VEGFA、bFGF水平和肿瘤组织中VEGFA、VEGFR2蛋白相对表达量均明显低于模型组(P均<0.05);血府逐瘀胶囊联合顺铂组血浆bFGF水平和肿瘤组织中VEGFR2蛋白相对表达量均明显低于模型组(P均<0.05)。结论血府逐瘀胶囊联合顺铂对Lewis肺癌荷瘤小鼠具有显著的抑瘤及抑制肿瘤血管新生的作用,其机制可能与VEGFA/VEGFR2信号通路相关。展开更多
目的:对比经上腹左胸手术和Ivor-lewis手术治疗SiewertⅡ型食管胃交界部腺癌(adenocarcinoma of the esophagogastric junction,AEG)在术中和术后各参数中的差别,以及患者预后的差异。方法:回顾性收集320例于河北医科大学第四医院胸外...目的:对比经上腹左胸手术和Ivor-lewis手术治疗SiewertⅡ型食管胃交界部腺癌(adenocarcinoma of the esophagogastric junction,AEG)在术中和术后各参数中的差别,以及患者预后的差异。方法:回顾性收集320例于河北医科大学第四医院胸外科行根治性手术的SiewertⅡ型AEG患者的数据,其中行上腹左胸手术的患者175例,行Ivor-lewis手术的患者145例。比较两组患者的临床病理特征、术中和术后情况、总生存时间(overall survival,OS)和无病生存时间(disease-free survival,DFS),并对影响AEG患者预后的情况进行单因素和多因素分析。结果:两组患者在肿瘤最大直径、pTNM分期、pN分期和下残阳性方面比较有统计学差异(P<0.05);与Ivor-lewis手术相比,行上腹左胸手术患者的术中时间缩短了30 min(P=0.034),术后吻合口瘘发生率更低(1.71%vs 4.83%,P=0.041);相比Ivor-lewis患者,行上腹左胸手术的患者可以获得更好的OS和DFS(P<0.05);单因素和多因素分析显示术前新辅助治疗是SiewertⅡ型AEG患者预后的影响因素(P<0.05)。结论:经上腹左胸手术可以彻底切除肿瘤,保留膈肌的完整,缩短开胸时间,有利于术后快速康复。同时,术后吻合口瘘等并发症的发生率低,有利于及时进行术后辅助治疗,更利于改善AEG患者的预后。展开更多
Since the discovery in 2011,MXenes have become the rising star in the field of two-dimensional materials.Benefiting from the metallic-level conductivity,large and adjustable gallery spacing,low ion diffusion barrier,r...Since the discovery in 2011,MXenes have become the rising star in the field of two-dimensional materials.Benefiting from the metallic-level conductivity,large and adjustable gallery spacing,low ion diffusion barrier,rich surface chemistry,superior mechanical strength,MXenes exhibit great application prospects in energy storage and conversion,sensors,optoelectronics,electromagnetic interference shielding and biomedicine.Nevertheless,two issues seriously deteriorate the further development of MXenes.One is the high experimental risk of common preparation methods such as HF etching,and the other is the difficulty in obtaining MXenes with controllable surface groups.Recently,Lewis acidic etching,as a brand-new preparation strategy for MXenes,has attracted intensive attention due to its high safety and the ability to endow MXenes with uniform terminations.However,a comprehensive review of Lewis acidic etching method has not been reported yet.Herein,we first introduce the Lewis acidic etching from the following four aspects:etching mechanism,terminations regulation,in-situ formed metals and delamination of multi-layered MXenes.Further,the applications of MXenes and MXene-based hybrids obtained by Lewis acidic etching route in energy storage and conversion,sensors and microwave absorption are carefully summarized.Finally,some challenges and opportunities of Lewis acidic etching strategy are also presented.展开更多
基金the funding support from the National Natural Science Foundation of China(Nos.22202036 and 22302001)the Jilin Province Scientific,the Technological Planning Project of China(No.20230101292JC).
文摘In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst.This catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)configuration.Compared to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the reaction.Within the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis acids.This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene selectivity.Through this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.
基金supported by the National Natural Science Foundation of China (52161025)the Natural Science Foundation of Gansu Province (20JR10RA241)。
文摘Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.
基金This work was supported by the National Natural Science Foundation of China(No.21876099)Shandong Provincial Natural Science Foundation(No.ZR2017PB007)Shandong Provincial Key Laboratory Project of Test Technology for Material Chemical Safety(No.2018SDCLHX005).
文摘Surface Lewis acid-base sites in crystal structure may influence the physicochemical properties and the catalytic performances in nanozymes.Understanding the synergistic effect mechanism of Co_(3)O_(4)nanozymes towards substances(3,3’,5,5’-tetramethylbenzidine(TMB)and hydrogen peroxide(H2O2))induced by surface Lewis acid-base sites is important to enhance the efficiency for peroxidase-like reaction.Herein,ultrathin porous Co_(3)O_(4)nanosheets with abundant Lewis acid-base sites were prepared by sodium borohydride(NaBH4)reduction treatment,which exhibited high-efficiency peroxidase-like activity compared with original Co_(3)O_(4)nanosheets.The Lewis acid-base sites for ultrathin porous Co_(3)O_(4)nanosheets nanozyme were owing to the coordination unsaturation of Co ions and the formation of defect structure.Ultrathin porous Co_(3)O_(4)nanosheets had 18.26-fold higher catalytic efficiency(1.27×10^(-2)s^(-1)·mM^(-1))than that of original Co_(3)O_(4)(6.95×10^(-4)s^(-1)·mM^(-1))in oxidizing TMB substrate.The synergistic effect of surface acid and base sites can enhance the interfacial electron transfer process of Co_(3)O_(4)nanosheets,which can be a favor of absorption substrates and the generation of reactive intermediates such as radicals.Furthermore,the limit of detection of hydroquinol was 0.58μM for ultrathin porous Co_(3)O_(4)nanosheets,965-fold lower than original Co_(3)O_(4)(560μM).Besides,the linear range of ultrathin porous Co_(3)O_(4)nanosheets was widely with the concentration of 5.0-1,000μM.Colorimetric detection of hydroquinol by agarose-based hydrogel membrane was provided based on excellent peroxidase-like properties.This study provided insights into designing high-performance nanozymes for peroxidase-like catalysis via a strategy of solid surface acid-base sites engineering.
文摘The systematic method for constructing Lewis representations is a method for representing chemical bonds between atoms in a molecule. It uses symbols to represent the valence electrons of the atoms involved in the bond. Using a number of rules in a defined order, it is often better suited to complicated cases than the Lewis representation of atoms. This method allows us to determine the formal charge and oxidation number of each atom in the edifice more efficiently than other methods.
文摘目的探讨血府逐瘀胶囊联合顺铂对小鼠Lewis肺癌移植瘤血管新生及血管内皮生长因子A(VEGFA)、血管内皮细胞生长因子受体2(VEGFR2)表达的影响。方法从75只C57BL/6小鼠中随机取15只作为正常组,其余小鼠均进行Lewis肺癌荷瘤造模。将造模成功的60只小鼠随机分为模型组、顺铂组、血府逐瘀胶囊组、血府逐瘀胶囊联合顺铂组,每组15只。血府逐瘀胶囊组给予血府逐瘀胶囊0.36 g/kg灌胃,模型组给予生理盐水灌胃,均2次/d;顺铂组给予2 mg/kg的顺铂腹腔注射,2 d 1次;血府逐瘀胶囊联合顺铂组给予0.36 g/kg血府逐瘀胶囊灌胃(2次/d)和2 mg/kg的顺铂腹腔注射(2 d 1次);正常组不给予任何干预。各组连续干预15 d后,统计存活率,摘取瘤组织并称量瘤重,计算抑瘤率,免疫组化法检测肿瘤组织中微血管数量,ELISA法测定血浆VEGFA、碱性成纤维细胞生长因子(bFGF)水平,免疫印迹法检测肿瘤组织中VEGFA、VEGFR2蛋白表达情况。结果顺铂组和血府逐瘀胶囊联合顺铂组小鼠存活率明显高于模型组和血府逐瘀胶囊组(P均<0.05);血府逐瘀胶囊联合顺铂组瘤重明显低于其他组(P均<0.05),抑瘤率明显高于顺铂组和血府逐瘀胶囊组(P均<0.05),肿瘤组织中微血管数明显少于模型组和血府逐瘀胶囊组(P均<0.05);顺铂组瘤重明显低于模型组和血府逐瘀胶囊组(P均<0.05),抑瘤率明显高于血府逐瘀胶囊组(P<0.05),肿瘤组织中微血管数明显少于其他组(P均<0.05)。顺铂组血浆VEGFA、bFGF水平和肿瘤组织中VEGFA、VEGFR2蛋白相对表达量均明显低于模型组(P均<0.05);血府逐瘀胶囊联合顺铂组血浆bFGF水平和肿瘤组织中VEGFR2蛋白相对表达量均明显低于模型组(P均<0.05)。结论血府逐瘀胶囊联合顺铂对Lewis肺癌荷瘤小鼠具有显著的抑瘤及抑制肿瘤血管新生的作用,其机制可能与VEGFA/VEGFR2信号通路相关。
文摘目的:对比经上腹左胸手术和Ivor-lewis手术治疗SiewertⅡ型食管胃交界部腺癌(adenocarcinoma of the esophagogastric junction,AEG)在术中和术后各参数中的差别,以及患者预后的差异。方法:回顾性收集320例于河北医科大学第四医院胸外科行根治性手术的SiewertⅡ型AEG患者的数据,其中行上腹左胸手术的患者175例,行Ivor-lewis手术的患者145例。比较两组患者的临床病理特征、术中和术后情况、总生存时间(overall survival,OS)和无病生存时间(disease-free survival,DFS),并对影响AEG患者预后的情况进行单因素和多因素分析。结果:两组患者在肿瘤最大直径、pTNM分期、pN分期和下残阳性方面比较有统计学差异(P<0.05);与Ivor-lewis手术相比,行上腹左胸手术患者的术中时间缩短了30 min(P=0.034),术后吻合口瘘发生率更低(1.71%vs 4.83%,P=0.041);相比Ivor-lewis患者,行上腹左胸手术的患者可以获得更好的OS和DFS(P<0.05);单因素和多因素分析显示术前新辅助治疗是SiewertⅡ型AEG患者预后的影响因素(P<0.05)。结论:经上腹左胸手术可以彻底切除肿瘤,保留膈肌的完整,缩短开胸时间,有利于术后快速康复。同时,术后吻合口瘘等并发症的发生率低,有利于及时进行术后辅助治疗,更利于改善AEG患者的预后。
基金supported by the Highstar Corporation HSD20210118Taihu Electric Corporation 0001。
文摘Since the discovery in 2011,MXenes have become the rising star in the field of two-dimensional materials.Benefiting from the metallic-level conductivity,large and adjustable gallery spacing,low ion diffusion barrier,rich surface chemistry,superior mechanical strength,MXenes exhibit great application prospects in energy storage and conversion,sensors,optoelectronics,electromagnetic interference shielding and biomedicine.Nevertheless,two issues seriously deteriorate the further development of MXenes.One is the high experimental risk of common preparation methods such as HF etching,and the other is the difficulty in obtaining MXenes with controllable surface groups.Recently,Lewis acidic etching,as a brand-new preparation strategy for MXenes,has attracted intensive attention due to its high safety and the ability to endow MXenes with uniform terminations.However,a comprehensive review of Lewis acidic etching method has not been reported yet.Herein,we first introduce the Lewis acidic etching from the following four aspects:etching mechanism,terminations regulation,in-situ formed metals and delamination of multi-layered MXenes.Further,the applications of MXenes and MXene-based hybrids obtained by Lewis acidic etching route in energy storage and conversion,sensors and microwave absorption are carefully summarized.Finally,some challenges and opportunities of Lewis acidic etching strategy are also presented.